I have changed our transfer switch since we have owned our unit, so I have a good idea of how they are arranged and wiried on our unit and most of them work the same.

When you pull the cover off the transfer switch it will show 3 basic feeds

The incoming shore power

The generator

The output to the house panel

When you are plugged into house power you will see power on the shore power input terminals and power on the house panel output terminals. Depending on where and how you measure it will be 110/220. Nothing on the gen power. Usually the shore power feed you can follow from the cord. The Generator will normally come in from the other side. The house big cable will be the one that is common to both input relays on the output side.

When you unplug the shore power and start up the generator you will see power on the generator input terminals and again on the house power terminals provided the relays are working properly.

Now when I had my problem I couldn't get any generator power inside with a volt meter plugged into an outlet. With the gen set running I had power 110/220 coming out of the generator and verified this by reading on the generator input terminals of the transfer relay. When I looked for the transfer out of the transfer relay on the generator side I did not have it. Ended up being the transfer relay on the generator side. Changed the transfer switch and haven't had any more problems.

That being said, you first step is to verify you have the proper power in and out of the gen Set and the shore power and both relays transfer power to the house panel in their own operation.

Now if all the power is good at all locations, your job will be to idenify the small wires also attached to your transfer switch which feed the inverter for normal charging. If you find the one for the shore power which you say is working then you should be able to find the same location on the generator transfer relay that does the same function. If the power is there and leaving from the Gen set side you will have to trace the wire to find out why the power is not getting to the inverter input from the Gen set side.

Remember the input wires will be the big # 6 wires and the control wires for your inverted will be some what smaller.

Can your generator switch be pushed in down (off) position and held there so you can get fault codes. Just had trouble with my 7.5 onan would run but no power out. Code was 3 blinks pause then 8 (code 38). Manual said turn off all appliances. Had left the 2 a/c's on when disconnected from shore power. If you can get a fault code that might help - maybe.

Slabman, I ran into a voltage texting quirk a few weeks back while testing the constant voltage source on a 65 Mustang. With my digital meter I was getting funny voltage when it should have been a pulsing 6-8 volts. I went back to my old analog meter and found the constant voltage source was puting out the pulsing 6 volts needed.

Thanks for the thoughts, guys...and John, sorry to keep you hanging. I am in Alamosa CO with the two grandsons enjoying the Nationals Parks. I spent several hours in ABQ and Durango working on this problem, but since we are going to be back home in Dallas on Thursday, I've decided to put this work on hold and spend more time with them. Probably won't get the chance to do this again....they are growing up too fast and I'm growing OLD too fast!

But I've been given a lot of ideas and am anxious to trace down all of them. I'm now of the opinion the problem is "downstream" from the inverters, towards the batteries. I'm going to hook up tow batteries and see if I can get that generator to charge with them...and go from there. I'm thinking there's also a possibility one of the new batts could be problematic, but this is hard to imagine with all new batteries back there. Anyway, I'll post on this again when I get more info. Thanks again for your help guys.

I ran into a voltage texting quirk a few weeks back while testing the constant voltage source on a 65 Mustang. With my digital meter I was getting funny voltage when it should have been a pulsing 6-8 volts. I went back to my old analog meter and found the constant voltage source was puting out the pulsing 6 volts needed. Apparently my cheap (Sears) digital voltmeter cannot use a pulsing voltage on DC.

tf - Unless you have a "True RMS" digital voltmeter, you can get some weird voltage readings when the voltage waveform is "unusual", like the modified sine-wave that some inverters produce, and perhaps in the case of pulsating DC voltages. Most inexpensive voltmeters aren't "True RMS", so in those cases it's nice to have a good old-fashioned analog meter to rely on when your readings don't make sense. Good luck. - Dave

OK, so here's some more food for thought for all us GENIUS types on this board! LOL!

I finally got under there and pulled the covers to both Magnums. With shore power off and the gen running, I measured 118.0v and 121.5 V RMS on the respective inverter inputs from the generator. Frequency was 60.5 HZ. Output voltages were essentially the same voltage...maybe a tenth less.

So then I went in and turned off the inverters and found the system to be charging continuously-the inverters not tripping out and the roof A/C's running, other loads applied, etc. But when turning the inverters to "on", they trip on/off, of course. Then I turned off the two 30 amp breakers downstream of the inverters' output and they still cycled on/off....however, for a brief second one of the remote display panels flashed in RED the words "A/C Overload". Again, this was with generator running and no shore power, inverters on and both downstream subpanel breakers (load) off.

So this appears to tell me the generator is OK, the transfer switch is fine, wiring to the inverters is OK, but something perhaps in the Magnums is amiss. If turning off the load downstream from the inverters doesn't help, it would appear downstream wiring is also OK.

Does this shed any light on the situation? I think I need to call Magnum once again and see what they think.
_________________

I finally got to talk to another guy at Magnum who went through settings on my remote display panel. He had me lower the normal settings for "A/C Cutout Voltage" from 100V to 80V. Now under generator power the inverters/chargers run just fine with no cutting in/out. While I'm ecstatic the issue seems to be resolved, I'm a little miffed the first two guys I spoke with DID NOT find anything wrong with those settings I was operating under. I asked him why I should think to operate under such a low figure as 80V. when clearly the generator was putting out about 120V...who woulda thunk it? He said that was just the way it was and sometimes that is what was required to make the inverters perform properly. So be it......

My thanks go out to all on this board who exerted their brain power in trying to resolve this issue-I truly appreciate all the input. It's nice to have so many offering their sincere efforts to resolve issues such as this....

Slabman,
I'm glad your problem seems to be resolved! But, I have a question and a comment or two if you don't mind.
There appears to be some confusion/misconception in terminology:
An "inverter" takes power from a direct current (DC) source - typically a battery - and inverts it into a sinusoidial (AC) waveform similar to commercial power.
A "converter" (or charger) takes power from an AC source - typically commercial or generator - and converts it into DC power for charging batteries and/or operating direct current loads.
At 80 amps, you are approaching the upper limit of your 10KW (83.3A @ 120VAC) genset. I suspect that your generator may be reaching it's full load output and cutting itself back. Have you added any new or larger loads recently?
Lastly, I don't even know what a Magnum is since my old gasser doesn't have one. However the advice to lower the cutoff voltage from 100V to 80V seems a bit radical to me. Could you lower it to some other value, i.e. 98V, 95V, and still get successful results? I would not lower it more than is required.
Just my thoughts.
Travis
Alvin, Texas